The invention relates to a device for bending, crimping, and trimming the leads of electrical components, particularly components whose leads are located on only one side of the component body, e.g. transistors. The device includes a supply container to store the components, two tools for bending and crimping, said tools working against one another and deforming the leads between them, followed by a cutting tool to trim the leads.
The invention is designed for use primarily only with those components in which the leads emerge on one side only, as is the case for transistors for example. The problem arises in this connection that these components, because of their unsymmetrical design, are difficult to transport continuously and to feed to a processing machine, and on the other hand the leads must be bent and crimped in different directions, so that the guide means as well as the tools must be made rather complicated. Devices known heretofore, therefore, do not operate completely automatically, but the components must be fed to the tools by hand. Thus, for example, it is known to feed the bodies of the components into recesses in a revolving plate, so that the leads extend upward. This revolving plate then moves past stationary processing tools and is stopped at each work station.
The efficiency of a machine of this type is naturally dependent on the one hand upon the working speed of the operator who places the components in the revolving plate and on the constant delays which result from braking the revolving plate at the work station and then accelerating it again.
An object of the invention is to provide a completely automatically operating device, which allows a considerable increase in production efficiency.
This object is achieved according to preferred embodiments of the invention which include the following provisions:
(a) the tools for bending and crimping are disposed pairwise along the periphery of a carrier rotating about an axis, with one of the tools being mounted relatively firmly and the other mounted swivelably in the rotational plane of the carrier or a plane parallel thereto; PA1 (b) the swivelable tool is controlled by a cam, which cam moves the swivelable tool during the rotation of the carrier from the open position of the tools into the closed position, or working position; PA1 (c) a conveyor which feeds the components one after the other to the tools is disposed between the supply container and the rotating carrier; PA1 (d) the conveyor is provided at the transfer point to the tools with a transfer slot disposed approximately at the level of the tools, extending in the direction of rotation of the latter, and open in this direction, in which a component is stored and through which its leads extend vertically downward, whereby PA1 (e) the swivelable tool is controlled by the cam in such manner that the component stored in the transfer slot when the tool is in the open position is gripped by the tool moving in the rotational direction, after which the tools are closed.
In contrast to many known prior art arrangements, the components in this invention are not placed in a rotating carrier and conveyed to stationary tools, but rather the components are placed in a stationary position in the transfer slot and automatically removed therefrom by the tool located further along the rotational direction. During rotation, the necessary movement for gripping and deforming the component between the tools is provided to the swivelably mounted tool during rotation by means of the cam. This means that it is no longer necessary to stop the carrier intermittently during processing, and to accelerate it again; instead, processing takes place during continuous rotation. Likewise, in the transfer area, there are no delays which reduce production efficiency because manual feed is eliminated. The production efficiency depends only upon the capacity of the conveyor. Such conveyor can theoretically be of a conventional design according to certain contemplated embodiments.
In a preferred embodiment, the carrier is a disc, so that several sets of tools can be disposed around its periphery if necessary.
The swivelable tool is preferably actuated by a spring which forces it into the open position, said spring being supported for example against the carrier disc.
The cam which serves to control the swivelable tool preferably consists of a circular section with a large diameter and a circular section of a small diameter, with abrupt transitions, whereby the small-diameter section is located approximately opposite the transfer point with the transfer slot. On the circular section with the large diameter, the tools are closed. In this position, the leads are deformed and trimmed. At the beginning of the abrupt transition to the small-diameter section (after the tools have performed bending and crimping), the movable tool is swiveled under the influence of the spring abutting it, so that the component is freed and can be ejected, for example by a stationary ejector. The tool reaches the maximum open position in the area of the curved section with the small diameter. At this time, the tools pass the transfer slot, so that one of the tools grips the component as it passes. As the carrier continues turning, the tool cam follower slides and/or rolls back up the steep transition to the large diameter, so that the tools close. An abrupt transition is recommended because this allows a particularly compact design. Moreover, this causes the opening and closing movement to be very rapid, so that the component does not drop out prematurely, for example as the tools close. For this reason, it is also preferred to make the slope of the curve which is responsible for closing the tool steeper than the one for opening the tool.
In many known machines, the leads are simply gripped between the tools and deformed. Since this results in forces being developed not only transversely to the leads but also in the direction of the leads, there is the danger that the leads will be torn out of the body of the component. Therefore, at least in rapidly operating machines, such as the device according to the invention, it is recommended to apply a tensile stress to the leads opposite the component body.
In order to produce such a tensile stress, according to the invention provision is made for having a holder or a brace located above each of the two tools for bending and crimping, which holders grip the leads of the components directly beneath the body of the component. In preferred embodiments said holders or braces are mounted with limited movement relative to the tool with which they are associated under the action of a spring and are provided with a stop, in such manner that during the closing movement of the swivelable tool the holder associated therewith is carried along until it comes to rest against the brace (at the other tool); and then, at the beginning of the actual working movement, the brace is also brought up against the spring supporting it, and finally, when the holder and brace come to a halt, the swivelable tool is moved into the closed position against the spring which supports the holder.
In this design, therefore, the leads are first gripped between the holder and the brace during the closing movement of the tool, and thereby relieve the body of the component from tension. Then, with the holder and brace participating in the movement, the leads are deformed in one direction, and then, with the holder and brace at rest, deformation is carried out in the opposite direction, since the swivelable tool can continue moving forward for the distance which is required for deformation while the holder and brace are stopped.
These and other objects, features and advantages of the present invention will become more apparent from the following description when taken in connection with the accompanying drawings, which show, for purposes of illustration only, a single embodiment in accordance with the present invention.